In‐situ biochar production associated with paddies: Direct involvement of farmers in greenhouse gases reduction policies besides increasing nutrients availability and rice production.

Treating soils with pyrolyzed biomass, that is biochar, is proposed as a conditioner and a carbon geoengineering measure. Rice is known as a strategic crop and rice husk is a cheap and available feedstock material for biochar in particular in Asia. We conducted a field experiment with laboratory biochar (LB) and locally produced [in‐situ biochar (IB)] applied at rates of 10 and 20 t ha−1 using a randomized block design in three replicates to examine the efficiency of IB for improving soil condition for rice production, and to propose a cheap and in‐farm applicable measure to decrease greenhouse gases (GHGs) emissions from the agricultural sector. Grain yield significantly increased following biochar addition by 52.2%, 53.2%, 65.4%, and 67.2% in LB10, IB10, LB20, and IB20, respectively. Total biomass in all biochar treatments had a significant difference (p < 0.05) compared with our control and the highest biomass belonged to LB20 and IB20 with 12.2 and 15.7 t ha1, respectively. The highest grain nitrogen, phosphorus, and potassium was in IB20. Compared to the control, IB20 significantly decreased emissions of CH4 by 72.3%, N2O by 85.8%, and CO2 by 32.9%. IB is as effective as LB. IB production and application provide a sustainable management approach for dealing with crop residues, improves soil conditions (aeration and nutrients availability) for crop growth, and directly and in a practical way involves farmers in GHGs reduction policies. [ABSTRACT FROM AUTHOR]